JP2002359414A - Huge magnetoresistive effect element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a GMR element capable of fully stabilizing a GMR laminated film magnetically, reading information with more sensitivity, and suppressing electro-migration. SOLUTION: A CPP type GMR element 1A comprises a GMR laminated film comprising a ferroelectric film, a non-magnetic film, and an antiferromagnetic film. Related to the GMR element, a sensing current Is flows in the direction vertical to the film surface of a GMR laminated film 2 thanks to an upper-part electrode 14 and a lower-part electrode 12. A hard magnetic film 3 is jointed directly, to both outsides in widthwise direction of the GMR laminated film 2. An insulation layer 4 is formed above or below the hard magnetic film 3. An opening between the insulation layers 4 on both sides regulates the path of the sensing current Is, between the upper-part electrode 14 or lower-part electrode 12 and the GMR laminated film 2. A high resistance film 31 is inserted in the hard magnetic film 3, which suppresses or prevents shunting of the sensing current Is into the hard magnetic film 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a giant magnetoresistive element in which a sense current flows in a direction perpendicular to the surface of a giant magnetoresistive laminated film.

[0002]

2. Description of the Related Art A magnetoresistive effect element (hereinafter referred to as "MR element")
A magnetic head is one of the electronic components that have been incorporated and put into practical use. For example, a magnetic head currently mounted on a hard disk drive has an inductive magnetic head for high-density magnetic recording and a magnetoresistive effect (Magnet Resist) for reading.
A composite magnetic head is used in combination with a magnetic head (MR head) using an ive (hereinafter simply referred to as “MR”).

FIG. 9 shows a schematic configuration diagram of this composite magnetic head. In FIG. 9, the gap film and the insulating film are omitted. The composite magnetic head 50 includes a magnetic sensing element 53 on a lower shield 52 made of a magnetic material formed on a substrate 51.
Are arranged, and an upper shield 54 made of a magnetic material is formed in an upper layer.

[0004] These lower shield 52, magneto-sensitive element 53,
The upper shield 54 constitutes a read magnetic head 61 as a lower layer head. As the magnetic sensing element 53, an element having a magnetoresistance effect, that is, an MR element is used.

The upper shield 54 also functions as a lower magnetic core of an upper head for recording, and a tip ball portion 55 is disposed above the upper shield 54. Tip ball 55
The upper magnetic core 57 is connected to the upper part of the upper magnetic core 57, and a back yoke 58 is connected to the rear of the upper magnetic core 57.
Then, a coil 56 is disposed between the lower magnetic core 54 and the upper magnetic core 57 and the back yoke 58 via an insulating layer.

The lower magnetic core 54, the coil 56, the tip ball 55, the upper magnetic core 57, and the back yoke 58
Thus, an inductive write magnetic head 62 is configured as an upper layer head.

The lower read magnetic head 61
And a write magnetic head 62 in the upper layer are laminated to form a composite magnetic head 50.

The M used for the MR head constituting the readout magnetic head 61 in the lower layer of the composite magnetic head 50
As the R element, a Giant Magnet Resistive (hereinafter, simply referred to as “GMR”) element having higher sensitivity has recently been used.

In a GMR element currently in practical use, a so-called CIP (Curren) in which a sense current for detecting a magnetoresistance effect flows in a direction parallel to the film surface of the GMR laminated film.
tIn Plane).

[0010]

However, this C
In the configuration of the CIP GMR element used in the IP mode,
In the future, when the recording density is further increased, it is considered that the limit will come soon from the viewpoint of the electrical short-circuit between the shield film and the hard film and the GMR laminated film for passing the sense current and the electromigration. I have.

For this reason, recently, the sense current has been reduced to GMR.
A so-called CPP (Curre) that flows vertically to the film surface of the laminated film.
nt Perpendicular to the P
The practical use of a CPP type GMR element used in a (lane) mode has been studied.

In the CPP type GMR element, the use of the shield film as an electrode eliminates the need for an insulating layer between the shield film and the GMR laminated film, so that the above-described short-circuit problem can be fundamentally solved.

Further, in the CPP type GMR element, since the contact area with the electrode film made of a metal film having good thermal conductivity becomes large, electromigration occurs even at a much higher current density than the CIP type GMR element. This makes it difficult to realize a narrow gap and a narrow track width required for a magnetic head for high-density recording.

FIG. 10 is a sectional view showing a schematic configuration of the conventional CPP type GMR element.

In the configuration of the GMR element 70 shown in FIG. 10, a conductive hard magnetic material is used for a hard magnetic film (hard film) 77 for stabilizing the GMR laminated film 73.

A GMR laminated film 73 having a trapezoidal cross section is formed on a lower magnetic shield 71 made of a magnetic material via a lower gap film 72 made of a nonmagnetic conductor and also serving as an electrode film. Although not shown, the GMR laminated film 73 is composed of a laminated film of a magnetic film, a nonmagnetic film, and an antiferromagnetic film. A hard magnetic film 77 made of a conductive hard magnetic material is provided on the left and right sides of the GMR laminated film 73 via an insulating film 76 such as an alumina film.
Is arranged. The insulating film 76 insulates the GMR film 73 from the conductive hard magnetic film 77. This hard magnetic film 7
An insulating layer 78 is also formed on the GMR laminated film 73, and an upper magnetic shield 75 made of a magnetic material is disposed on the insulating layer 78 via an upper gap film 74 made of a nonmagnetic conductor. ing. The upper gap film 74 also serves as an electrode film, and is connected to the GMR laminated film 73 through an opening (width W) between the left and right insulating layers 78.

The lower magnetic shield 71 and the lower gap film 72 serve as lower electrodes, and the upper magnetic shield 75 and the upper gap film 74 serve as upper electrodes. Through these electrodes, the GMR laminated film 73 is perpendicular to the film surface of the laminated film. The sense current Is can flow in the direction. Further, the GMR laminated film 73 can be magnetically stabilized by the hard magnetic film 77.

In the structure shown in FIG. 10, each layer has the following functions.

The lower magnetic shield 71 and the upper magnetic shield 75 serve to limit the signal magnetic field entering the GMR film 73 in order to increase the recording density in the recording medium in the linear direction. The material of the shields 71 and 75 is N
iFe, FeN, etc. can be used.

Lower gap film 7 made of non-magnetic conductor
The second and upper gap films 74 magnetically separate the shields 71 and 75 from the GMR laminated film 73. CIP type GM
In a GMR head provided with an R element, it was necessary to use an insulating material such as alumina for the gap film in order to insulate the shield from the GMR laminated film. In contrast, CP
In a GMR head having a P-type GMR element, the GMR laminated film 7 is formed through a lower gap film 72 and an upper gap film 74.
3 to allow the sense current Is to flow through the lower gap film 72.
For the upper gap film 74, a conductive material is used. For example, Au, Cu, Ta or the like can be used.

When the signal magnetic field entering the GMR film 73 from the recording medium changes, the electrical resistance of the GMR film 73 changes correspondingly. At this time, by passing the sense current Is through the GMR film 73, a change in resistance can be detected as an output.

Here, the GMR film 73 and the hard magnetic film 77
Is desirably sufficiently thin from the viewpoint of a stabilizing magnetic field applied to the GMR laminated film 73.

If the insulating film 76 is thick, the hard magnetic film 77 causes a spacing loss in the stabilizing magnetic field applied to the magnetization free layer of the GMR laminated film 73, so that the GMR laminated film 73 can be sufficiently stabilized. However, Barkhausen noise and hysteresis noise are generated.

In consideration of variations in the film formation state in the process of forming the insulating film 76 and an increase in the number of processes due to the film forming process, it is desirable to eliminate the insulating film 76 if possible.

Here, the spacing loss due to the insulating film between the GMR multilayer film and the hard magnetic film will be examined by simulation.

As shown in FIG. 11, the width Wl is 100 nm.
A hard magnetic film (hard film) 83 is disposed on the left and right of the GMR laminated film 81 via an insulating film 82 made of Al2O3.
Using the model of the MR element 80, the distribution d of the magnetic field in the GMR laminated film 81 for each amount d was calculated by changing the amount d of spacing by the insulating film 82.

FIG. 12 shows the result of the calculation. The vertical axis of FIG. 12 indicates the case where the hard magnetic film 83 is directly in contact with the GMR laminated film 81 without an insulating film (spacing amount d = 0). (X = 50n
(position of m) is the strength of the magnetic field normalized with the ideal value of the strength of the magnetic field obtained at 1. In FIG. 12, due to the influence of the calculation method, the value at the position of x = 50 nm when d = 0 is not the ideal value of 1.

FIG. 13 shows the change in the normalized magnetic field intensity at the center of the GMR laminated film 81. This figure 1
The vertical axis in the case of No. 3 is the central part of the GMR laminated film 81, ie
The magnetic field strength is normalized by setting the magnetic field strength (about 0.17 in FIG. 12) to 1 when the spacing amount d = 0 at the position of x = 0 in FIG.

12 and 13, the larger the spacing d of the insulating film 82 is, the larger the GMR laminated film 8 is.
It can be seen that the stabilizing magnetic field within 1 is reduced.

In order to solve the above-mentioned problems, the present invention provides a GMR element capable of sufficiently stabilizing a GMR laminated film magnetically, reading information with higher sensitivity, and suppressing electromigration. It is.

[0031]

Therefore, in the first aspect of the present invention, the giant magnetoresistive element comprises a giant magnetoresistive laminated film having a ferromagnetic film, a nonmagnetic film and an antiferromagnetic film,
A giant magnetoresistive element in which a current flows in a direction perpendicular to the film surface of the giant magnetoresistive laminated film by the upper electrode and the lower electrode, and a hard magnetic material is provided on both outer sides in the width direction of the giant magnetoresistive laminated film. A magnetic film is formed by direct bonding, an insulating layer is formed above or below the hard magnetic film, and the upper electrode or the lower electrode and the giant magnetoresistive effect stack are formed by openings between the insulating layers on both sides. A high-resistance film for regulating a current path to a film and suppressing or preventing a shunt of the current flowing into the hard magnetic film is provided in the hard magnetic film to solve the problem. are doing.

According to the second aspect of the present invention, the giant magnetoresistive element comprises a giant magnetoresistive laminated film having a ferromagnetic film, a non-magnetic film and an antiferromagnetic film, and is formed by an upper electrode and a lower electrode. A giant magnetoresistive element in which a current flows in a direction perpendicular to the film surface of the giant magnetoresistive laminated film, wherein a hard magnetic film is directly bonded to both outer sides in the width direction of the giant magnetoresistive laminated film. Forming an insulating layer on or below the hard magnetic film, and restricting a current path between the upper electrode or the lower electrode and the laminated film by an opening between the insulating layers on both sides, The hard magnetic film has a specific resistance equal to or higher than the specific resistance of the giant magnetoresistance effect laminated film, and a high-resistance film for suppressing or preventing the shunt of the current flowing into the hard magnetic film. The hard magnetic film is interposed in the The have solved.

Further, according to the third aspect of the present invention, the giant magnetoresistive element is composed of a giant magnetoresistive laminated film having a ferromagnetic film, a non-magnetic film and an antiferromagnetic film, and includes an upper electrode and a lower electrode. A giant magnetoresistive element in which a current flows in a direction perpendicular to the film surface of the giant magnetoresistive stacked film,
Hard magnetic films are formed by directly bonding hard magnetic films on both outer sides in the width direction of the giant magnetoresistive laminated film, and on both of these hard magnetic films, a path of a current flowing into the giant magnetoresistive laminated film is regulated,
Further, the problem is solved by interposing a high-resistance film for suppressing or preventing the shunt of the current flowing into the hard magnetic film.

A plurality of the high resistance films may be laminated and interposed in the hard magnetic film, and the high resistance film may be a permanent magnet, a soft magnetic material or a non-magnetic material.

Therefore, according to the giant magnetoresistive element of the first aspect of the present invention, the sense current which is shunted to the two hard magnetic films is effectively suppressed or blocked, and the sense current is transmitted to the giant magnetoresistive laminated film. It can be energized effectively.

According to the giant magnetoresistive element of the second aspect of the present invention, both the hard magnetic films are made of a high resistance film having a specific resistance equal to or higher than that of the giant magnetoresistive laminated film. The sense current that is shunted to the two hard magnetic films can be more effectively suppressed or prevented, and the sense current can be more effectively supplied to the giant magnetoresistive laminated film.

Further, according to the giant magnetoresistive element of the third aspect of the present invention, in addition to the above-described effects, the giant magnetoresistive effect film flows into the giant magnetoresistive effect laminated film only by the high resistance films provided on both the hard magnetic films. The current path can be regulated.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, a CPP type giant magnetoresistive element (CPP type GMR
The element will be described.

As described above, in order to read information with even higher sensitivity, all of the sense currents must be equal to G shown in FIG.
It is desirable to flow in the MR laminated film 73, and the GMR
In order to sufficiently stabilize the laminated film magnetically, it is desirable to eliminate the insulating film 76 between the GMR laminated film 73 and the hard magnetic film 77 as much as possible. However, when the insulating film 76 is eliminated, there is a possibility that the sense current is shunted to the hard magnetic film 77.

Therefore, when the insulating film 76 was removed and the hard magnetic film was directly joined to the GMR element, it was examined how much current would leak to the hard magnetic film.

First, FIG. 1 shows a schematic sectional view of the CPP type GMR element used in the study.

The sectional structure of the CPP type GMR element 1 shown in FIG. 1 uses a conductive hard magnetic material for the hard magnetic film 3 for stabilizing the GMR film 2. In the sectional structure shown in FIG. 1, the magnetic shields 11 and 15 are provided above and below the GMR laminated film 2 as in the case of applying to a GMR head or a thin film magnetic sensor.
Is provided.

The GMR laminated film 2 is formed on a lower magnetic shield 11 made of a magnetic material via a lower gap film 12 made of a non-magnetic conductor and also serving as an electrode film.

Although not shown, the GMR laminated film 2 is composed of a laminated film having a ferromagnetic film, a non-magnetic film, and an antiferromagnetic film, and has a trapezoidal cross section.

A hard magnetic film (hard film) 3 made of a conductive hard magnetic material is disposed on both left and right sides of the GMR laminated film 2 in a structure directly bonded to the GMR laminated film 2.

On the hard magnetic film 3, an insulating layer 4 is formed so as to extend over the GMR laminated film 2. On the insulating layer 4, an upper gap film 14 made of a non-magnetic conductor also serves as an electrode film. , Is connected to the GMR laminated film 2 through an opening (width W) between the left and right insulating layers 4.

The lower magnetic shield 11 and the upper magnetic shield 15 serve to limit the magnetic field entering the GMR film 2. As a material of the lower magnetic shield 11 and the upper magnetic shield 15, NiFe, FeN, or the like can be used.

Lower gap film 1 made of non-magnetic conductor
2 and the upper gap film 14 magnetically separate the shields 11 and 15 from the GMR laminated film 2. Gap film 12
For example, Au, Cu, Ta, or the like can be used as the material of (14).

The lower magnetic shield 11 and the lower gap film 12 serve as lower electrodes, and the upper magnetic shield 15
And the upper gap film 14 serves as an upper electrode, through which a sense current Is can flow through the GMR laminated film 2 in a direction perpendicular to the film surface direction of the laminated film.
The MR element 1 is configured.

When the magnetic field in the GMR film 2 changes, the electrical resistance of the GMR film 2 changes accordingly. At this time, a change in resistance can be detected as an output by flowing the sense current Is through the GMR laminated film 2.

Further, the hard magnetic films 3 on both the left and right sides make the GM
The R laminated film 2 can be magnetically stabilized.

Since the insulating layer 4 formed on the hard magnetic film 3 is formed so as to overlap the GMR film 2, the GMR film 2, the upper electrode 14 and the lower electrode 15 are electrically connected to each other. The width W of the connection part to be electrically connected is determined by the distance between the insulating layers 4 on both sides in this part.

In the GMR multilayer film 2 having the structure shown in FIG. 1, the current efficiency in the GMR multilayer film 2 was examined by changing the specific resistance ρ of the hard magnetic film 3. The current efficiency is defined as current efficiency = (current flowing through the GMR laminated film) / (current flowing through the GMR laminated film + hard magnetic film) in a plane where the magnetization free layer directly contributes to the output in the GMR laminated film 2. Flowing current).

FIG. 2 shows a change in current efficiency due to a change in the specific resistance ρ of the hard magnetic film 3. The horizontal axis of FIG.
Specific resistance / specific resistance of MR laminated film 2 (specific resistance of hard magnetic film 3 / GM
R specific film 2). The GMR laminated film 2
Corresponds to the combined specific resistance of the entire laminated film of the GMR laminated film 2. Hereinafter, the same applies, although not otherwise specified.

FIG. 2 shows that if the specific resistance ρ of the hard magnetic film 3 is at least equal to or higher than the specific resistance of the GMR laminated film 2,
It can be seen that a sufficiently high current efficiency of about 0% can be obtained.

As a result of this study, the hard magnetic film 3 was
By using a hard magnetic material having a specific resistance equal to or higher than that of the MR laminated film 2, even if the insulating film 76 between the GMR laminated film 2 and the hard magnetic film 3 is omitted, from the viewpoint of leakage current, Does not cause a major problem. Rather, the hard magnetic film 3 can be brought closer to the GMR laminated film 2 to effectively stabilize the GMR laminated film 2, and the manufacturing process can be simplified. It is thought that great advantages can be obtained from.

Next, the reason why the result shown in FIG. 2 is obtained will be considered.

In the sectional structure of FIG.
FIG. 3 shows the result of calculating the current density distribution in the inside. The horizontal axis in FIG. 3 is a distance y (nm) from the center of the GMR multilayer film 2,
The vertical axis is the current density J normalized with the maximum value as 100. Note that the width of the opening in the insulating layer 4 on the upper electrode side is GMR.
It is 50 nm (= W / 2) from the center of the laminated film.

As shown in FIG. 3, the current density is high inside the opening of the insulating layer 4, but the current density outside the opening of the insulating layer 4 gradually decreases as the distance from the opening increases.

FIG. 4 schematically shows the distribution of the sense current Is in the GMR film 2 shown in FIG.

The sense current Is flows from the upper electrode to the GMR film 2 through the opening of the insulating layer 4. GM
The sense current Is spreads in the width direction (horizontal direction in the drawing) in the R laminated film 2 and the hard magnetic film 3, but the magnitude (current density) of the sense current Is decreases as the distance from the opening of the insulating layer 4 increases. That is, as shown in FIG. 4, most of the sense current Is passes through the GMR laminated film 2 to such an extent that it spreads slightly from the opening of the insulating layer 4.

At this time, the specific resistance of the hard magnetic film 3 is G
If the specific resistance is larger than the specific resistance of the MR laminated film 2, the spread of the current from the GMR laminated film 2 to the hard magnetic film 3 is significantly reduced.

From the above, if the specific resistance of the hard magnetic layer film 3 is set to be equal to or more than the specific resistance of the GMR laminated film 2, the GMR
Even if the laminated film 2 and the conductive hard magnetic film 3 are formed in direct contact, the leakage of the sense current Is to the hard magnetic film 3 is considered to be sufficiently small.

Therefore, the CPP of the first embodiment of the present invention
In the type GMR element 1A, as shown in FIG. 5, the hard magnetic film 3 in the GMR element 1 shown in FIG. 1 or FIG.
In the structure, the high resistance film 31 is interposed horizontally on the film surface of the GMR laminated film 2 to increase the specific resistance of the hard magnetic film 3. In addition,
The other components are the same as the components of the GMR element 1, and thus the same reference numerals are given and the description thereof will be omitted.

CPP GMR of First Embodiment of the Present Invention
By configuring the element 1A with such a structure, the specific resistance ρ of the hard magnetic film 3 is apparently equal to or higher than the specific resistance of the GMR laminated film 2 with respect to the sense current Is. Can be.

Therefore, even if a part of the sense current Is flowing from the opening of the insulating layer 4 tries to shunt from the GMR multilayer film 2 to the hard magnetic film 3, such a shunt can be suppressed or prevented.

The material of the hard magnetic film 3 is, for example, Co
A high resistance film 31 made of a conductive hard magnetic material such as CrPt is used.
For example, Co-γ-Fe2O3 (cobalt gamma hematite) can be used. As the ultimate high resistance film 31, there is an insulator, which may be used. Further, the high resistance film 31 may be a permanent magnet, a soft magnetic material or a non-magnetic material.

In FIG. 5, the gap width Ta is 60n.
m, if the thickness Tb of the hard magnetic film 3 is 40 to 50 nm,
The thickness Tc of one high-resistance film 31 is about 3 to 5 nm.

The position where the high-resistance film 31 is inserted should be located near the magnetic free layer of the GMR element 2 and the magnetic field from the hard magnetic film 3 must sufficiently stabilize the GMR multilayer film 2 sufficiently. The effect of the insertion position of the high resistance film 31 differs depending on the location. In particular, if only one high-resistance film 31 is used, it is difficult to select an insertion position. Therefore, it is preferable to stack a plurality of thin high-resistance films 31 in the thickness direction of the hard magnetic film 3. The GMR according to the second embodiment of the present invention constituted by this structure
The element 1B is shown in FIG. The portion of the hard magnetic film 3 of the GMR element 1B is composed of a laminated film of a high resistance film 31 and a hard magnetic film 32. The materials of the high-resistance film 31 and the hard magnetic film 32 may be the same as those described above.

By forming the hard magnetic film 3 in such a laminated structure, it is possible to cut off the sense current Is that is going to flow into the hard magnetic film 3 from above the GMR element 2.

However, on the other hand, there is a problem of magnetic stabilization of the GMR multilayer film 2. As the number of high resistance films 31 to be inserted increases, the magnetic field generated as the hard magnetic film 3 decreases, and the magnetic stabilization decreases. Therefore, the position and the number of the hard magnetic films 3 are determined so that the GMR multilayer film 2 can be sufficiently stabilized, and can be designed according to the configuration of the GMR multilayer film, the magnitude of the sense current flowing through the element, and the like. .

Further, the present inventors have proposed that a hard magnetic film 3 having a specific resistance ρ approximately equal to or higher than the specific resistance of the hard magnetic layer film 3 as a CPP type GMR element is formed on both left and right sides of the GMR laminated film 2. Is arranged so as to be directly bonded to the semiconductor device, and as compared with the case where an insulating film is provided between the GMR laminated film 2 and the hard magnetic film 3,
The hard magnetic film 3 is brought closer to the GMR laminated film 2 so that G
A structure was proposed in which the MR laminated film 2 was stabilized, thereby reducing Barkhausen noise, hysteresis noise, and the like. The CPP type GMR element etc.
Patent Application No. 2001-085843 filed on May 23, 2009, entitled "Giant magnetoresistance effect element, magnetoresistance effect type head, thin film magnetic memory, and thin film magnetic sensor".

A magnetic film of CoCrPt is used as a hard magnetic film in the CPP type GMR element. In particular,
The composition of CoCrPt is, for example, Co: Cr: Pt = 7.
By setting the ratio to 8:10:12 (atomic ratio%), the specific resistance of the hard magnetic film 3 can be made higher than the specific resistance of the GMR laminated film 2. And a hard magnetic film 3 having good magnetic properties
Can be formed.

In such a CPP type GMR element, it is preferable to insert at least one high resistance film 31 in the hard magnetic film (hard film) as in the structure of the CPP type GMR elements 1A and 1B. With such a structure, the hard magnetic film can further surely suppress or prevent the shunt of the sense current Is flowing from the GMR element.

In the CPP type GMR elements 1A and 1B of these embodiments, the insulating layer 4 on the hard magnetic film
Since the current path between the upper gap film 14 serving as an upper electrode and the GMR laminated film 2 is regulated by the openings of the insulating layers 4 on both sides formed over the laminated film 2, the center of the GMR laminated film 2 is It is also possible to concentrate the sense current Is on the portion so as not to leak to the hard magnetic film 3. With such a formation, a sufficient current density can be ensured in the GMR laminated film 2.

Further, the CPP type GMR element 1A of the present invention,
According to 1B, since it is not necessary to form an insulating layer between the GMR multilayer film 2 and the hard magnetic film 3, the number of steps can be reduced,
The manufacturing process can be simplified, and the influence of variations in the formation of the insulating film can be eliminated.

Further, the CPP type GMR element 1 of the present invention
According to A and 1B, since the hard magnetic film 3 is directly bonded to the GMR laminated film 2, heat is diffused from the GMR laminated film 2 to the hard magnetic material 3, so that the GMR laminated film is resistant to electromigration. 2 can improve the reliability.

In FIGS. 1 and 4 to 6, the insulating layer 4 is formed by GMR.
Although formed on the laminated film 2, an insulating layer is disposed below the GMR laminated film, and an opening of the insulating layer defines a current path between the lower electrode and the GMR laminated film 2. You may. In this case, the same effect can be obtained.

In FIGS. 1 and 4 to 6, the insulating layer 4 is formed over (overlapping with) the GMR laminated film 2, but the insulating layer 4 is located at those positions. Is not limited. For example, the edge of the insulating layer 4 may coincide with the interface between the GMR multilayer film 2 and the hard magnetic film 3 or may be further closer to the hard magnetic film 3 than this interface.

In the present invention, the CPP type GMR element 1C according to the third embodiment of the present invention shown in FIG. 7 and the CPP type GMR element 1D according to the fourth embodiment of the present invention shown in FIG.
As described above, the structure may be such that both insulating layers 4 are omitted. That is, both the upper and lower electrodes 1 are hard magnetic films.
Even in contact with the hard magnetic films 2, 14, the branching of the sense current can be suppressed by the opening interval of the high resistance film 31 inserted between the hard magnetic films 3, and the path of the sense current can be defined. Other configurations and operations of the CPP type GMR element 1C and the CPP type GMR element 1D are respectively similar to those of the CPP type GMR element 1C.
Since these are almost the same as those of the element 1A and the CPP type GMR element 1B, their description will be omitted.

The present invention is not limited to the above-described embodiment, and can take various other configurations without departing from the gist of the present invention. Further, the GMR element of the present invention comprises:
It should be noted that the present invention can be applied to a GMR head, a thin-film magnetic memory, and a thin-film magnetic sensor.

[0082]

As described above, according to the present invention,
A hard magnetic film is directly bonded to a GMR laminated film of a GMR element, and the hard magnetic film is formed of a high-resistance film, so that an insulating film is provided between the GMR laminated film and the hard magnetic film. , By bringing the hard magnetic film closer to the GMR laminated film,
By stabilizing the MR laminated film, the resistance change of the GMR laminated film can be stabilized. Thereby, in the GMR element, Barkhausen noise, hysteresis noise, and the like are reduced.

Further, by setting the specific resistance of the hard magnetic film to be equal to or higher than that of the GMR laminated film, the sense current can be concentrated and flow in the GMR laminated film without leaking to the hard magnetic film.

Further, since the insulating layer is formed above or below the hard magnetic film, G
Since the current path between the MR laminated film and the upper electrode or the lower electrode is regulated, the current can be biased toward the center of the GMR laminated film so as not to leak to the hard magnetic film. Therefore, a sufficient current density can be ensured in the GMR laminated film.

Further, since there is no need to form an insulating film between the GMR layer film and the hard magnetic film, the number of steps can be reduced, the manufacturing process can be simplified, and the film thickness of the insulating film can be reduced. The influence of the variation can be eliminated.

Therefore, according to the present invention, the manufacturing cost can be reduced and the manufacturing yield can be improved.

[Brief description of the drawings]

FIG. 1 CPP in which a hard magnetic film is directly bonded to a GMR element
FIG. 2 is a cross-sectional view conceptually showing a configuration of a type GMR element.

FIG. 2 is a graph showing a change in current efficiency in the GMR element when the specific resistance of the hard magnetic film is changed in the GMR element shown in FIG.

3 is a graph showing a distribution of a normalized current density in a width direction of the GMR element in the GMR element shown in FIG.

FIG. 4 is a sectional view schematically showing a state of a current flowing in the CPP type GMR element shown in FIG.

FIG. 5 is a sectional side view conceptually showing the configuration of the CPP type GMR element of the first embodiment of the present invention.

FIG. 6 is a sectional side view conceptually showing a configuration of a CPP type GMR element according to a second embodiment of the present invention.

FIG. 7 is a sectional side view conceptually showing a configuration of a CPP type GMR element according to a third embodiment of the present invention.

FIG. 8 is a sectional side view conceptually showing a configuration of a CPP type GMR element according to a fourth embodiment of the present invention.

FIG. 9 is a schematic configuration diagram of a general composite magnetic head.

FIG. 10 is a sectional view conceptually showing the configuration of a conventional CPP type GMR element.

FIG. 11 is a configuration diagram of a model for performing a simulation on a spacing loss caused by an insulating film between the GMR element and the hard magnetic film.

12 is a graph showing a calculation result of a change in a magnetic field distribution in the GMR element due to a change in the amount of spacing in the model shown in FIG. 13;

13 is a graph showing a calculation result of a change in the magnitude of a magnetic field at the center of the GMR element due to a change in the amount of spacing in the model shown in FIG. 13;

[Explanation of symbols]

1: CPP type giant magnetoresistance effect element (GMR element), 1
A: CPP type giant magnetoresistive element (GMR element) of the first embodiment of the present invention, 1B: C of the second embodiment of the present invention
PP type giant magnetoresistive element (GMR element), 2 ... GM
R laminated film, 3, 32 hard magnetic film (hard film), 31 high resistance film, 4 insulating layer, 11 lower magnetic shield, 12
Lower gap film, 14: Upper gap film, 15: Upper magnetic shield

Continuation of the front page (72) Inventor Naoji Terada 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation (72) Inventor Shigehisa Ogawara 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 2G017 AC01 AD55 AD56 AD62 AD63 AD65 5D034 BA03 BA08 BA12 BA15 BB08 CA00 5E049 AA01 AA07 AC00 AC05 BA12 CB02 DB12

Claims (7)

[Claims] 1. A giant magnetoresistive laminated film having a ferromagnetic film, a nonmagnetic film, and an antiferromagnetic film, wherein an upper electrode and a lower electrode are arranged in a direction perpendicular to the film surface of the giant magnetoresistive laminated film. A giant magnetoresistive element through which an electric current flows, wherein a hard magnetic film is formed by directly bonding both outer sides in the width direction of the giant magnetoresistive laminated film, and is insulated on or below the hard magnetic film. A layer is formed, and a current path between the upper electrode or the lower electrode and the giant magnetoresistive laminated film is regulated by openings between the insulating layers on both sides, and the current flowing to the hard magnetic film is restricted. A giant magnetoresistive element, wherein a high-resistance film for suppressing or preventing a shunt is inserted in the hard magnetic film. 2. A giant magnetoresistance effect laminated film having a ferromagnetic film, a nonmagnetic film, and an antiferromagnetic film, wherein an upper electrode and a lower electrode extend in a direction perpendicular to the film surface of the giant magnetoresistance effect laminated film. A giant magnetoresistive element through which a current flows, wherein a hard magnetic film is formed by directly bonding both outer sides in the width direction of the giant magnetoresistive laminated film, and is insulated on or below the hard magnetic film. A layer is formed, and an opening between the insulating layers on both sides restricts a current path between the upper electrode or the lower electrode and the laminated film, and the hard magnetic film has a specific resistance of the giant magnetoresistive laminated film. And a high-resistance film for suppressing or preventing the shunt of the current flowing into the hard magnetic film is inserted into the hard magnetic film. Giant magnetoresistance effect element. 3. A giant magnetoresistive laminated film having a ferromagnetic film, a non-magnetic film and an antiferromagnetic film, wherein an upper electrode and a lower electrode extend in a direction perpendicular to the film surface of the giant magnetoresistive laminated film. A giant magnetoresistive element through which an electric current flows, wherein a hard magnetic film is formed by directly joining both outer sides of the giant magnetoresistive effect laminated film in the width direction; A giant magnetism characterized in that a high resistance film is interposed to regulate the path of the current flowing into the effect laminated film and to suppress or prevent the shunt of the current flowing into the hard magnetic film. Resistance effect element. 4. The giant magnetoresistive element according to claim 1, wherein a plurality of said high resistance films are stacked and interposed. 5. The giant magnetoresistive element according to claim 1, wherein the high-resistance film is a permanent magnet. 6. The giant magnetoresistance effect element according to claim 1, wherein said high resistance film is a soft magnetic material. 7. The giant magnetoresistive element according to claim 1, wherein the high-resistance film is a non-magnetic material.